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In order to develop an eco-friendly superabsorbent composite, flax yarn waste (FYW) was used as raw material to synthesize a novel flax yarn waste-g-poly(acrylic acid-co-acrylamide) (FYW/PAA) superabsorbent composite. Acrylic acid (AA) and acrylamide (AM) were grafted onto the pretreated flax yarn waste (PFYW) by free-radical graft copolymerization in homogeneous aqueous solution. The properties and synthesis conditions of the FYW/PAA superabsorbent composite were investigated. As a result, the prepared FYW/PAA attained the best water absorbency of 875 g/g in distilled water, 490 g/g in rainwater and 90 g/g in 0.9 wt% NaCl solution. The urea loading percentage of FYW/PAA could be modulated by the concentration of urea. The release of urea from FYW/PAA in water showed a typical three-stages sustained release behavior. Meanwhile, a weight residue of 53.6 wt% was attained after being buried in soil for 90 d., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Abstract: A new, low-cost, and eco-friendly cellulose-based superabsorbent was successfully prepared from flax yarn waste. The method used was a free-radical graft copolymerization of AA and AM onto a cellulose backbone in a homogeneous aqueous solution. APS was used as the initiator in the presence of a crosslinker, MBA. The effects of various factors on water absorbency were discussed. The factors included reaction temperature, initiator amount, monomer amount, salt solution type, and solution pH. Under the optimized conditions, the water absorbencies of the obtained superabsorbent composite were 875g/g distilled water, 490g/g natural rainwater, and 90g/g 0.9wt% aqueous NaCl solution. The product also had excellent water retention and salt resistance properties. Fourier-transform infrared spectroscopy and scanning electron microscopy were employed to examine the structure of the prepared superabsorbent. [Copyright &y& Elsevier]